A hinge mechanism usually can be used with a notebook computer, a mobile telephone set and the like. In practice, the hinge mechanism is connected between the main body and the monitor of the notebook computer such that they can be pivoted relative to each other, or connected between the main body and the transmitter plate of the mobile telephone set such that they can be pivoted relative to each other. The present invention has arisen for a hinge mechanism which can be operated easily and conveniently.